Question: What is the voltage across the capacitor after one time constant in an RC charging circuit?

Options:

1. V(1 - e^(-1))
2. V(1 + e^(-1))
3. V/e
4. V

Correct Answer: V(1 - e^(-1))

Solution:

After one time constant, the voltage across the capacitor is V(1 - e^(-1)), where V is the applied voltage.